public class UniquePathsWithObstacles {

// https://leetcode.cn/problems/unique-paths-ii/
    class Solution {
        public int uniquePathsWithObstacles(int[][] obstacleGrid) {

            int m = obstacleGrid.length;
            int n = obstacleGrid[0].length;
            int [][] dp = new int[m][n];
            if(obstacleGrid[0][0] == 1|| obstacleGrid[m-1][n-1] == 1) return 0;
            for(int i = 0 ; i < m ; i ++)
            {
                if(obstacleGrid[i][0] == 1) break;
                dp[i][0] = 1;
            }
            for(int i = 0 ; i < n ; i ++)
            {
                if(obstacleGrid[0][i] == 1) break;
                dp[0][i] = 1;
            }

            for(int i = 1 ; i < m ; i ++)
            {
                for(int j = 1 ; j < n ; j ++)
                {
                    if(obstacleGrid[i][j] == 1) continue;
                    dp[i][j] = dp[i-1][j] + dp[i][j-1];
                }
            }
            return dp[m-1][n-1];

        }
    }
}
